Support bar for underground workings



May 28, 1953 A. VANWERSCH ETAL SUPPORT BAR FOR UNDERGROUND WORKINGS 2 Sheets-Sheet 1 Filed July 23, 1959 INVENTORS J Man/954 4 U5 M; C HIV/V445 lpgfl 7 E ap usA/uEQ May 28, 1963 A. VANWERSCH ET AL 3,091,083

SUPPORT BAR FOR UNDERGROUND WORKING-S Filed July 25, 1959 2 Sheets-Sheet 2 w HIS U ix.

iinited rates Fatent 3, 9i,h8 8 Patented May 28, 1953 free 3,091,088 SWEGRT BAR FOR UNDERGROUND WORKlNGS Aioys Vanwersch, Heiderweg 7, Angermuud, Germany;

Ludwig Vanwersch, Reuleauxstr. 16, Eschweiler, Germany; and Peter Vanwersch, Rolandstr. 20, Aachen, Germany Filed July 23, 1959, Ser- No. 828,935 Ciaims priority, application Germany July 25, 1958 Claims. (Q1. 61-45) For propping or support purposes in mines, in particular for support purposes in underground workings, use is made of support bars which are adapted to be pivotally connected to each other and which can be pressed, by wedge effect, against the rock.

Known bars of this kind have a fork at one end and a tongue at the other end. In order to connect two bars together, the tongue end of one bar is inserted in the forked end of the next bar. The two bars are pivotally connected together with the aid of a swivel pin which is pushed through apertures in the two connecting ends. In the forked end is a second pair of apertures into which a wedge can be passed, the wedge surface of the wedge being driven against one surface of the tongue end which in part intersects the wedge apertures in the fork. By this means, one bar already being fixed in position, the second bar is forced to pivot about the swivel pin towards the roof of wall, and the wedge secures the bar in its supporting position.

The known bars are generally symmetrical relatively to a longitudinal central plane. A construction of this kind of the bars makes it possible to continue to use a bar which has become slightly bent due to strong roof pressure, by rotating the bent bar through 180 about its longitudinal axis. The pressure of the roof or wall now acts on the other side of the bar, so that the bent bar is straightened.

The invention relates to a support bar which is symmetrical about a longitudinal central plane, and has as its object the simplification of the construction and handling of the bar, the bar being so constructed that it can easily be erected and removed by one man.

According to the invention, there are provided at one of the ends two apertures which are arranged side by side in the longitudinal central axis of the bar and whereof one aperture is adapted to receive the swivel pin and the other aperture is adapted to receive the wedge, the other end of the bar having a wedge aperture located in the said longitudinal central axis and, adjacent the said wedge aperture, two swivel pin apertures which are displaced to opposite sides of the said longitudinal central axis.

The connecting ends may be designed as a fork and tongue respectively. The apertures, which are displaced to opposite sides of the longitudinal central axis, for the swivel pins, can preferably be formed at the tongue end.

It is especially advantageous to form the swivel pin apertures which are displaced to opposite sides of the longitudinal central axis at a distance from the outer end face of the bar which is equal to or smaller than half the height of the bar at its connecting ends.

Embodiments of the invention are shown in the accompanying drawings, wherein:

FIG. 1 is a fragmentary side elevation, partly in section, showing a connection between two bars according to one embodiment of the invention;

FIG. 2 is a cross-section taken on line 22 of FIG. 1; and

FIG. 3 is a fragmentary side elevation of the disengaged ends of the bar connection shown in FIGS. 1 and 2.

FIG. 4 is a fragmentary side elevation, partly in section,

of a bar connection according to another embodiment of the invention;

FIG. 5 is a fragmentary side elevation of the disengaged ends of the bar connection shown in FIG. 4; and

FIGS. 6 and 7 are fragmentary side elevations of the bar connection shown in FIG. 4, showing different stages of erection of the bars.

FIGS. 8, 9, 10 and 11 are fragmentary side elevations of bar connections according to other embodiments of the invention.

FIGS. 12 and 13 show, respectively, a side elevation and section on line 13l3 of FIG. 12, of another embodiment of the invention.

In the various figures of the drawings, only those portions of the bars in the zone of the connection between two bars are shown. Each bar is symmetrical about a longitudinal central plane. Each bar has a medial portion 3 with a fork at one end 1 and a tongue at the other end 2. The connecting means in all the embodiments shown are a swivel pin 4 and a wedge 5 which can be secured against undesired loosening and displacement by means of a retarding spring 6.

The retarding springs 6 are so positioned in the fork end of the bar that they can not be removed when removing the swivel pin 4- or the wedge 5. The retarding springs are provided with two shoulders 6a radially projecting to the internal side, which shoulders are being pressed against the surfaces of the swivel pin or Wedge preferably against grooves in said swivel pin or wedge, when the latter are driven in. The retarding springs are not necessarily constructed in the form of a closed ring. They may e.g. be formed semicircular and the ends carry the shoulders 6a which project into the grooves 5a of the wedge 5 or appropriate grooves of the swivel pin 4. The longitudinal grooves 5a have, at their ends, abutment surfaces 5b which bear against the shoulders 6a and thus prevent the wedge being drawn completely out of the bar end 1. The retarding springs 6 are kept in situ by a stop ring 17 or the like. For retarding the swivel pin or wedge every element resiliently pressed against the surface of said elements will sufi'ice.

The bars in the connection shown in FIGS. 1 to 3 have at the forked end 1 two pairs of apertures 7 and 8. The pair of apertures 7 receives the swivel pin 4, and the pair of apertures 8 receives the wedge 5. All the said apertures 7 and 8 are positioned with their centres on the longitudinal central axis of the bar. The tongue end 2 of the bar has an aperture 811, to receive the wedge 5, the centre of the aperture 8a also being on the longitudinal central axis of the bar. Adjacent the wedge aperture 8a, at the tongue end 2, are apertures 7a and 7b for swivel pin 4, the said apertures being displaced in the upward and downward direction, respectively, to opposite sides of the longitudinal central axis of the bar.

In order to connect the bars together, the bar with the fork end 1 at the intended connection already being fixed in position, the tongue end 2 of a new bar to be erected is inserted in the forked end of the erected bar and the swivel pin apertures 7, 7a on the two connecting ends are brought into alignment with each other. The swivel pin 4 can then be pushed through the apertures 7 and 7a, so that the new bar is pivotally connected to the erected bar and, for the time being, hangs downwardly. The upper surface 3a of the erected bar bears against the roof, when bars are to support the roof, and is supported by a prop 20 shown in broken lines in FIG. 1. The new bar can now be pivoted upwardly until the wedge apertures S and 8a in the connecting ends 1 and 2 are substantially in alignment with each other. Then the wedge 5 can be driven into the wedge apertures 8 and 8a.

It will be apparent that, due to the opposed displace- :can be removed.

;are on the longitudinal central axis of the bar.

ment of the swivel pin apertures 7a and 7b relative to the central axis of the bar, the wedge apertures 8 and 8a only partially intersect each other when the two bars are disposed substantially in alignment with each other, the wedge aperture 8a in the tongue end 2 being displaced below the wedge apertures 8 in the forked end 1. When the wedge is driven into the Wedge apertures the bar with the tongued end 2 is forced upwardly towards the roof, and when the said bar makes contact with the roof the bar is caused to press tightly against the roof by further driving in of the wedge 5.

In FIG. 1, 'the bar having the tongue end 2 is so erected that its upper surface 2a as shown in the figure bears against the roof. It is of course also possible to erect the bar in its reversed position, that is, after a rotation through 180 about its longitudinal axis, so that the lower surface 2b shown in FIG. 1 then is uppermost and bears against the roof; in this case, the swivel pin 4 is passed through the aperture 7b, instead of the aperture 70, for the pivotal connection of the two bars.

If the bar carrying the forked end 1 is to be removed, once the bar carrying the tongue-like end 2 has been sup ported by means of a prop, then first of all the prop 20 The bar will remain in the position supporting the roof. In order to disconnect the bar, the swivel pin 4, which may be slightly conical, can be knocked out of the connection. The bar with the forked end 1 then pivots downwardly about the connecting wedge 5. Alternatively, it is possible to first remove the pivot pin 4 and subsequently remove the prop 20.

The spacing of the pivot pin apertures 7a and 7b from the extreme outer end 20 of the tongue 2 preferably is so selected that it is, at most, equal to half the height of the bars in the zone of their connecting ends. This facilitatesthe upward pivoting of the new bar out of its depending position into its horizontal position, since the connecting end, that is, the tongue 2, does not project beyond the profile of the bar as it is pivoted and thus cannot come into contact with the roof.

With the bar connection according to FIGS. 4- to 7,

the apertures 7a and 7b for the swivel pin 4, and the "apertures for the wedge 5 at the connecting ends 1 and 2 have been interchanged. The tongue end 2 has two apertures located in the longitudinal central axis, that is, an

.aperture 7 to receive the swivel pin and an aperture 8a to receive the wedge. On the forked end 1 is a pair of axially aligned wedge .apertures 8 the centres of which The swivel pin apertures 7a and 7b which are displaced equally to opposite sides of the longitudinal central axis of the bar are provided in the forked end, in front of the wedge apertures 8.

In FIG. 4, the previously erected bar is designated 3 and the new bar to be connected therewith is designated 3 For the purpose of connecting the bar 3 to the bar 3, the forked end 1 of the bar 3 is pushed over the tongue end 2 of the bar 3 and the swivel pin 4 is inserted in the coinciding apertures 7 and 7a. The bar 3 now hangs vertically downwardly (FIG. 6) and can be swung up out of this pivoting position into the position shown in FIG. 7. The wedge 5 can now be driven into the partially coinciding apertures 8 and 8a. It will be apparent from FIGS. 4 to 7 that, when the wedge 5 is driven into the apertures 8 and 8a, the bar 3 ispivoted upwardly.

When the bar 3 is to be disconnected, preferably the swivel pin4 is first of all removed, so that the bar 3 is enabled to pivot downwardly about the wedge 5. The

' we'dge 5 then is removed and the bar 3 can be removed a from the bar 3 In the bar connection according to FIG; 8, which substantially corresponds to the one illustrated in FIGS. 1 to 3, the space between the forks of the forked end 1 has a bottom surface 21 which constitutes an arc of .a circle having a radius which is designated R. The axis of the are of this surface 21 coincides with the centre of the swivel pin aperture '7. The vertically suspended bar 3 bears, at the point 21a, against the end edge of the forkend surface 21 of the bar 3 which is supported by a prop (not shown). The swivelling of the bar 3 is limited thereby. A constructionof this nature of the connecting ends of the bars makes it possible to use the bars as a retaining means for the working face. A surface of the bar 3 that is, the righthand surface in FIG. 8, then bears against the working face, for example against the coal face, and prevents the working face falling into the working space or cavity.

In the embodiment, according to FIG. 9, the bar 3 is held in an inclined position relatively to the bar 3. The bottom surface of the space between the forks of the forked end of the bar 3, against which the bar 3 bears, is in this case provided with two adjacent arcuate surfaces 22. The radius of a said surface 22 is designated 1'.

The bar connection according to FIG. 10 corresponds substantially to that according to 1 IGS. 4 to 7 except that the bottom surface of the space between the forks is formed as an arc of a circle, designated 21. The abutment of the bar 3 against the end edge of the surface 21 is effected in the vertical suspended position at the point 21b.

With the arrangement according to FIG. 11, the bottom surface of the space between the forks is subdivided in two adjacent arcuate surfaces 22. The abutment of the bar 3 on the bar 3 is, in this case again, eifected to retain the bar 3 in an inclined position.

The bar connection according to FIGS. 12 and 13 corresponds to that according to FIGS. .1 to 3. The swivel pin 4 is, in this case however, formed with recesses 4a. The swivel pin 4 is inserted in the apertures in the connecting ends 1 and 2 in such manner that the recesses 4a are positioned substantially vertically one above the other. The pin bears laterally against the bounding surfaces of the apertures. Consequently, the forces transmitted from the swivel pin to the connecting ends of the bars are so influenced in their direction that they act substantially towards both sides. The narrow web between the adjacent swivel pin apertures 7a and 7b is thus relieved of load.

Instead of the recesses or flattened portions 4a of the swivel pin 4, it is possible to form the swivel pin apertures with recesses above and below, which said recesses prevent the cross-sectionally round swivel pin from bearing above and below against the aperture walls.

The swivel-pin and wedge apertures may be round, or have any other shape. correspondingly, the wedges can also have any suitable shape, for example they may be rectangular.

While the invention has been described in detail with reference to the specific embodiments shown, various changes and modifications will become apparent to the skilled artisan which fall into the spirit of the invention and scope of the appended claims.

We claim:

1. For use in a mine roof support, in combination,

an elongated bar having a longitudinal plane of symmetry and being formed at one end portion thereof with a pair of apertures therethrough at least one of which being a circular aperture, said apertures having their axes located spaced from each other a given distance in said plane of symmetry, said one of said apertures being adapted to receive a swivel pin and the other of said apertures being adapted to receive a wedge, said :bar being formed at the other end portion thereof with an aperture having an axis located in said plane of symmetry and a pair of circular swivel pin apertures of substantially the same diameter as said circular apertures at said one end portion and the axes of said additional circular swivel pin apertures being respectively located at opposite sides of said plane of symmetry and spaced from said one aperture at said other end portion said given distance,

whereby when one bar is supported against a mine roof, a new bar may be connected thereto by placing a swivel pin in the circular aperture at the one end portion of the one bar and through one of said circular swivel pin apertures at the other end portion of the new bar and by then driving a wedge through the other aperture at the one end porti n of said one bar and through said one aperture at the other end portion of said new bar and whereby the new bar, when bent under the load acting thereon, may be turned through 180 about its axis and reconnected to said one bar by placing the swivel pin through the other of said circular swivel pin apertures of the new "bar.

2. For use in a mine roof support, in combination, a pair of elongated bars having each a longitudinal plane of symmetry and an end portion overlapping the end portion of the other bar, one of said bars being formed in said end portion thereof with a pair of apertures therethrough having substantially parallel axes located in said plane of symmetry spaced from each other a preselected distance, at least one of said apertures being a circular aperture, the other of said bars being formed with a first aperture therethrough having its axis located in the plane of symmetry of said other bar and two additional apertures of circular configuration and having axes substantially parallel to the axis of said first aperture and being respectively spaced therefrom said preselected distance and the axes of said additional apertures being respectively located on opposite sides of said plane of symmetry, one of said additional apertures of said other bar being aligned with said one aperture of said one bar and said first aperture of said other bar being at least partly aligned with the other aperture of said one bar; a pivot pin extending through said aligned apertures; and a wedge member extending through said partly aligned apertures.

3. An arrangement as defined in claim 2 in which the distance of the axis of each additional aperture from the free end face of said other bar is at most equal to halt the height of said one bar at said end portion thereof.

4. An arrangement as defined in claim 2 in which said end portion of one of said bars being constructed as a tork and said end portion of the other [of said bars being in the form of a tongue located between the branches of said fork.

5. An arrangement as defined in claim 4 in which said first and said two additional apertures being vformed through said end portion in the form of a tongue.

6. An arrangement as defined in claim 4 and including abutment means formed at said end portion of said one bar and adapted to engage said end portion of the other bar when said wedge member is removed to limit tilting movement of said other bar about said pivot pin with respect to said one bar to an angle of less than 90.

7. An arrangement as defined in claim 6 in which said abutment means is formed by a rounded face extending between the branches of Said fork.

8. An arrangement as defined in claim 4 and including retarding springs located in said apertures of said one bar and adapted to bear resiliently against the surfaces of said pivot pin and said wedge member, respectively.

9. An arrangement as defined in claim 8 in which said pivot pin and said wedge member are formed with circumferential grooves defining shoulders on said pivot pin and said Wedge member, respectively, adapted to bear against end faces of said retarding springs, respectively.

10. An arrangement as defined in claim 8 in which the retarding springs have a circular form.

References Cited in the file of this patent FOREIGN PATENTS 722,202 Great Britain Ian. 19, 1955 80,173 Netherlands Ian. 16, 1956 774,109 Great Britain 1957 199,149 Austria 1958 OTHER REFERENCES Germany, application 1,027,613; printed April 10, 1958 (K1. 9/10). 

1. FOR USE IN A MINE ROOF SUPPORT, IN COMBINATION, AN ELONGATED BAR HAVING A LONGITUDINAL PLANE OF SYMMETRY AND BEING FORMED AT ONE END PORTION THEREOF WITH A PAIR OF APERTURES THERETHROUGH AT LEAST ONE OF WHICH BEING A CIRCULAR APERTURE, SAID APERTURES HAVING THEIR AXES LOCATED SPACED FROM EACH OTHER A GIVEN DISTANCE IN SAID PLANE OF SYMMETRY, SAID ONE OF SAID APERTURES BEING ADAPTED TO RECEIVE A SWIVEL PIN AND THE OTHER OF SAID APERTURES BEING ADAPTED TO RECEIVE A WEDGE, SAID BAR BEING FORMED AT THE OTHER END PORTION THEREOF WITH AN APERTURE HAVING AN AXIS LOCATED IN SAID PLANE OF SYMMETRY AND A PAIR OF CIRCULAR SWIVEL PIN APERTURES OF SUBSTANTIALLY THE SAME DIAMETER AS SAID CIRCULAR APERTURES AT SAID ONE END PORTION AND THE AXES OF SAID ADDITIONAL CIRCULAR SWIVEL PIN APERTURES BEING RESPECTIVELY LOCATED AT OPPOSITE SIDES OF SAID PLANE OF SYMMETRY AND SPACED FROM SAID ONE APERTURE AT SAID OTHER END PORTION SAID GIVEN DISTANCE, WHEREBY WHEN ONE BAR IS SUPPORTED AGAINST A MINE ROOF, A NEW BAR MAY BE CONNECTED THERETO BY PLACING A SWIVEL PIN IN THE CIRCULAR APERTURE AT THE ONE END PORTION OF THE ONE BAR AND THROUGH ONE OF SAID CIRCULAR SWIVEL PIN APERTURES AT THE OTHER END PORTION OF THE NEW BAR AND BY THEN DRIVING A WEDGE THROUGH THE OTHER APERTURE AT THE ONE END PORTION OF SAID ONE BAR AND THROUGH SAID ONE APERTURE AT THE OTHER END PORTION OF SAID NEW BAR AND WHEREBY THE NEW BAR, WHEN BENT UNDER THE LOAD ACTING THEREON, MAY BE TURNED THROUGH 180* ABOUT ITS AXIS AND RECONNECTED TO SAID ONE BAR BY PLACING THE SWIVEL PIN THROUGH THE OTHER OF SAID CIRCULAR SWIVEL PIN APERTURES OF THE NEW BAR. 